Blower adapter assembly

ABSTRACT

The invention describes an airflow adapter for a blower having an outlet duct, and which includes a closed, substantially tubular conduit having an mating section and an exit cylinder, the mating section shaped to mate with the outlet duct of the blower, and having selected geometry to complement the cross-sectional geometry of the outlet duct of the blower, and wherein the exit cylinder has a circular cross-section. Intermediate the mating section and the exit cylinder is a transitional chamber providing a continuous flowpath between the mating section and the exit cylinder. The invention also includes abutment means adjacent the mating section for aligning the adapter relative to the blower. The adapter has a longitudinal axis parallel to the flowpath of a selected length along its longitudinal axis such that the combination of the transitional chamber and the exit cylinder is configured to eliminate air separation from the internal surface of the exit cylinder.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to an adapter for a blower/fan assembly. More particularly, the present invention relates to an adapter for a blower/fan assembly that focuses and directs the air in a selected manner.

[0003] 2. Background of the Invention

[0004] There exists a market for a blower/fan configured to blow air internal to hollow, flexible objects for the purpose of placing the object in an erect position. The air flowing into or through the object is generated by a blower at the base of the object and connected to it by a passage or plenum of the blower assembly. The radial flow centrifugal fan, also known as a “squirrel cage” type of blower, is commonly used because it is efficient and compact. The blower/fan assembly is contained within a scroll-shaped, volute housing that ends at an exit end. The exit end typically has an extended elliptical cross-section, with parallel walls.

[0005] In known fashion, as described in U.S. Pat. No. 6,146,092 to Botros, et al., the blower wheel pulls air into the blower housing 20. The amount of air moved by the blower increases as a point on the wheel moves within the housing from an edge of the inlet opening of the housing. The housing is positioned progressively further from the wheel in the direction of rotation to accommodate the growing volume of air due to the volute shape of the housing. The blower action produces a stream of high velocity air that is ejected from the exit end of the housing, hereinafter referred to as the “exit channel.” The high velocity stream tends to stay together hugging the walls of the passage adjacent the edges. As the air continues to impact upon the side-wall edges of the passage way, air separation occurs at 14, 16, as shown in FIG. 1 of the '092 patent. Such air separation causes the airflow to be uneven upon exit from blower.

[0006] However, it is desirable that the air velocity through the passage from the blower housing to the hollow, flexible objects be uniform and that separation of the airflow be prevented to maintain the hollow, flexible objects in a solid, erect manner.

[0007] The apparatus of the '092 overcomes this air separation problem by providing a centrifugal blower assembly adapter for use which uses a non-linear, non-planar shaped adapter/diffuser disposed between the centrifugal blower housing and the object. This apparatus is designed to work with a heat exchanger and is too cumbersome and expensive to use with hollow, flexible objects.

[0008] The apparatus of the invention overcomes the problems of air separation, provides an adapter that induces an even airflow throughout the cross-section of the exit channel, and provides an adapter assembly that is inexpensive and easily adaptable to the centrifugal blower assembly.

SUMMARY OF THE INVENTION

[0009] As described above, and as shown in FIG. 1, the centrifugal blower is disposed in a generally scroll-shaped housing including an air inlet side, a bottom side opposite the air inlet side and a generally cylindrical, curved wall extending between the air inlet side and the bottom side. These sides define a volute chamber through which a volume of air passes, the chamber terminating in an exit channel end including a cut-off edge section. Due to the air separation on the walls of the exit channel, the centrifugal blower produces a stream of non-uniform airflow through the blower housing through the exit channel. Numerous shapes and configurations of adapters were tested to find an adapter that would eliminate the air separation at the side walls of the blower exit duct, and direct the airflow uniformly in parallel with the desired direction of flow. The present invention comprises an adapter sized and configured to mate with the exit duct of the blower.

[0010] It is an advantage of the present invention that airflow separation is eliminated in an efficient and compact adapter. These and other features and advantages of the present invention will become apparent from the drawings, detailed description and claims that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a perspective view of the adapter of the invention mounted on a typical centrifugal air blower.

[0012]FIG. 2 is a perspective view of the adapter of the invention.

[0013]FIG. 3 shows a top view of the adapter of the invention.

[0014]FIG. 4 shows a side cross-sectional view of the adapter of the invention.

[0015]FIG. 5 is a front cross-sectional view of the adapter of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Referring now to the drawings, FIG. 1 shows a typical centrifugal blower/fan assembly 20, to which the adapter 100 of the invention has been attached. The blower assembly 20 has a carrying handle 25 and an operating switch 30. Exit channel 40 of assembly 20 is typically of generally extended ellipsoidal cross-section, having two opposing parallel straight sides and two opposing semi-circular sides. However, the present invention is not limited in the type of blower assembly, such that it could be affixed to a fan blade type blower. The blower assembly may have an exit channel of any geometric shape. It is only necessary that the adapter be constructed to fittingly mate with the blower assemble exit channel. FIG. 2 is a perspective view of adapter 100, showing essentially a tubular structure having a complementary mating section 140, of similar extended ellipsoidal cross-section and sized to mate with the exit channel 40 of blower assembly 20, and extending to an exit cylinder 180 of generally cylindrical shape, having a circular cross-section. Intermediate to the mating section 140 and the exit cylinder 180 is a transitional chamber 160 providing a flow path for the air from mating section 140 to exit cylinder 180, and wherein the inner surface of transitional chamber 160 smoothly funnels from the extended ellipsoidal cross-section to circular cross-section. Referring to FIGS. 3, 4 and 5, mating section 140 has a depth d of about 2 inches a length l of about 19 inches, and a width w of about 4.5 inches, with the external radii r of semicircular mating ends 142 and 144 about 2.25 inches. Disposed on parallel sides 146 and 148 are blocks 150, which serve as abutment means for exit channel 40 when adapter 100 is mounted on blower assembly 20. The dimensions of blocks 150 are not critical to the invention. In the preferred embodiment, each block is rectangular, of about 4 inches in length, and with a square cross-section of 1 in sides. Blocks 150 arc evenly spaced on parallel sides 146 and 148, displaced inwardly about 1.25 inches from the external rim of mating section 140. Alternatively, abutment means could be formed by fabricating a ridge about the internal surface of mating section 140, displaced from its external rim about the same distance and blocks 150. Other abutment means would be obvious to one of ordinary skill in the art.

[0017] Transitional chamber 160 extends from the internal rim 152 of mating section 140 and funnels somewhat conically to provide a path for expansion of the airflow from mating section 140 to exit cylinder 180. Chamber 160 has a depth dd of about 5.25 inches, and evolves the extended ellipsoidal cross-section of mating section 140 to the circular cross-section of exit cylinder 180. The radius R of exit cylinder 180 is about 8.5 inches, with a depth D of about 5 inches. Given the above dimensions, the cross-sectional area of mating section 140 is about 90.154 inches, and the cross-sectional area of exit cylinder 180 is about 226.98 inches, providing a ratio of the cross-section of the mating section 140 to the cross-section of the exit cylinder 180 of about 1:2.5. One of ordinary skill in the art would appreciate that dimensions for mating section 140 may vary based on the size and configuration of the blower assembly, and that the depth and cross-sectional dimensions of exit cylinder 180 may also vary to achieve elimination of the air separation for different output requirements.

[0018] Experimentation has shown that the overall length of the adapter, the sums of d, dd and D, is optimally at least 12 inches. If the adapter is shorter than about 12 inches, air does not have sufficient space to fully expand between the mating section 140 and the exit cylinder 180, thereby not eliminating the induced air separation.

[0019] Additionally shown on FIGS. 2, 3 and 5 are recesses 165 that are formed in the exterior surface of transitional chamber 160, which recesses 165 may be used to aid in mounting adapter 100 to blower assembly 20. Recesses 165 serve a fictional purpose, but are not structurally necessary for operation of adapter 100.

[0020] The Adapter 100 is easily secured to the blower assembly 20 by means of VELCRO® strips, i.e., a complementary pair of strips consisting of one strip of fabric of small hooks that sticks to a corresponding strip of small loops. A pair of strips of either hooks or loops, shown as adapter strips 200, are attached to the external surface of mating section 140, and a pair of the complementary strips are affixed to blower assembly 20 (not shown), and located on the exit channel 40 such that when the adapter 100 is mounted on blower assembly and the exit channel 40 abuts against blocks 150, adapter strips 200 span the distance to the blower assembly 20 and complementarily mate with the blower assembly strips (not shown) to secure adapter 100 to blower assembly 20. One of ordinary skill in the art would recognize that there are many ways of securing adapter 100 to blower assembly 20, of which the Velcro® strip method is just one, for example, the adapter may be permanently affixed to the blower assembly by drilling complementary holes in both adapter and blower assembly, and securing the adapter to the blower assembly by means of metal screws. However, the use of Velcro® strips is preferred so that the adapter may be readily removed from the blower assembly for ease of shipping and transport.

[0021] While the present description contains much specificity, they should not be construed as limitations on the scope of the invention, but rather as an exemplification of one/some preferred embodiment/s thereof. Accordingly, the scope of the invention should not be determined by the specific embodiments illustrated herein, but rather in light of the full scope of the claims appended hereto. 

What is claimed is:
 1. An airflow adapter for a blower having an outlet duct, the adapter comprising a closed, substantially tubular conduit having a mating section and an exit cylinder, the mating section shaped to mate with the outlet duct of the blower, the exit cylinder having a circular cross-section, the adapter having a transitional chamber between the mating section and the exit cylinder, the transitional chamber providing a flowpath between the mating section and the exit cylinder, and wherein the dimensions of combination of the transitional chamber and the exit cylinder are selected so as to eliminate air separation from the internal surface of the exit cylinder.
 2. The adapter of claim 1 wherein the cross-sectional geometry of the mating section is selected to complement the cross-sectional geometry of the outlet duct of the blower.
 3. The adapter of claim 2 wherein the mating section is sized to receive the outlet duct of the blower.
 4. The adapter of claim 2 wherein the mating section is sized to encapsulate the outlet duct of the blower.
 5. The adapter of claims 2 wherein the mating section is of generally extended ellipsoidal cross-section, having two opposing parallel straight sides and two opposing semi-circular sides.
 6. The adapter of claim 1 additionally comprising abutment means adjacent the mating section, the abutment means for aligning the adapter relative to the blower.
 7. The adapter of claim 1 wherein the adapter has a longitudinal axis parallel to the flowpath, and the adapter has a selected length along its longitudinal axis.
 8. The adapter of claim 7 wherein the selected length is from about 12 inches to about 15 inches.
 9. The adapter of claim 8 wherein the ratio of the cross-section of the mating section to the cross-section of the exit cylinder is about 1:2.5.
 10. The adapter of claim 1 additionally comprising means for securing the adapter to the blower.
 11. An airflow adapter for a blower having an outlet duct, the adapter comprising: (a) a closed, substantially tubular conduit having an mating section and an exit cylinder, the mating section shaped to mate with the outlet duct of the blower, the cross-sectional geometry of the mating section selected to complement the cross-sectional geometry of the outlet duct of the blower; (b) the exit cylinder having a circular cross-section; (c) a transitional chamber between the mating section and the exit cylinder, the transitional chamber providing a flowpath between the mating section and the exit cylinder; (d) abutment means adjacent the mating section, the abutment means for aligning the adapter relative to the blower; and wherein the combination of the transitional chamber and the exit cylinder is configured to eliminate air separation from the internal surface of the exit cylinder.
 12. The adapter of claim 11 wherein the mating section is sized to receive the outlet duct of the blower.
 13. The adapter of claim 11 wherein the mating section is sized to encapsulate the outlet duct of the blower.
 14. The adapter of claims 11 wherein the mating section is of generally extended ellipsoidal cross-section, having two opposing parallel straight sides and two opposing semi-circular sides.
 15. The adapter of claim 11 wherein the adapter has a longitudinal axis parallel to the flowpath, and the adapter has a selected length along its longitudinal axis.
 16. The adapter of claim 15 wherein the selected length is from about 12 inches to about 15 inches.
 17. The adapter of claim 1 wherein the ratio of the cross-section of the mating section to the cross-section of the exit cylinder is about 1:2.5.
 18. The adapter of claim 11 additionally comprising means for securing the adapter to the blower.
 19. An airflow adapter for a blower having an outlet duct, the adapter comprising: (a) a closed, substantially tubular conduit having an mating section and an exit cylinder, the mating section shaped to mate with the outlet duct of the blower, the cross-sectional geometry of the mating section selected to complement the cross-sectional geometry of the outlet duct of the blower; (b) the exit cylinder having a circular cross-section; (c) a transitional chamber between the mating section and the exit cylinder, the transitional chamber providing a continuous flowpath between the mating section and the exit cylinder; (d) abutment means adjacent the mating section, the abutment means for aligning the adapter relative to the blower; and wherein, the adapter has a longitudinal axis parallel to the flowpath, the adapter having a selected length along its longitudinal axis, and the combination of the transitional chamber and the exit cylinder is configured to eliminate air separation from the internal surface of the exit cylinder.
 20. The adapter of claim 19 wherein the mating section is sized to receive the outlet duct of the blower.
 21. The adapter of claim 19 wherein the mating section is sized to encapsulate the outlet duct of the blower.
 22. The adapter of claims 19 wherein the mating section is of generally extended ellipsoidal cross-section, having two opposing parallel straight sides and two opposing semi-circular sides.
 23. The adapter of claim 19 wherein the selected length is from about 12 inches to about 15 inches.
 24. The adapter of claim 19 wherein the ratio of the cross-section of the mating section to the cross-section of the exit cylinder is about 1:2.5.
 25. The adapter of claim 19 additionally comprising means for securing the adapter to the blower. 